Hydraulic pressure control valve for automobile brake mechanism

ABSTRACT

A hydraulic pressure control valve for an automobile brake mechanism which is provided with a first hydraulic pressure passage communicating with each brake units of, for instance, front wheels, and a second hydraulic pressure passage communicating with each brake units of, for example, rear wheels, and in which a plunger 5 is disposed in at least one or both of the hydraulic pressure passages and at least one hydraulic pressure regulating mechanism for converting the hydraulic pressure of a brake liquid as desire for instance, a poppet valve 14, is provided in association with the plunger in the hydraulic pressure passage having disposed therein the plunger, and in which blocking member is provided for inhibiting the plunger 5 from moving in a direction in which to cut off the brake liquid when the hydraulic pressure of either one of the hydraulic pressure passages fails. The blocking member is composed of a moving member 10 moved by a difference in pressure between the both hydraulic pressure passages and a pressurizing member 17 for generating a pressure on the plunger by the movement of the moving member.

FIELD OF THE INVENTION

The present invention relates to a hydraulic pressure control valve foran automobile brake mechanism, and more particularly to a hydraulicpressure control valve which is disposed in an automobile braking systembetween its master cylinder and brake units to regulate a braking forcefor brakes of front and rear wheels. This invention is especiallyapplicable for the rear brake units which is not equipped with a y-sealsubject to hydraulic pressures from both sides thereof, unlike in theprior art, but are capable of partly restoring a braking force byinhibiting a plunger from moving in a direction in which to cut off abrake liquid upon failure of a liquid passage leading to each brake unitof either the front or rear wheels.

BACKGROUND OF THE INVENTION

In an automobile speed control mechanism, a braking force is usuallyconverted by a hydraulic braking system into a hydraulic pressure of abrake liquid for transmission to each brake unit. With the hydraulicbraking system, a force applied thereto from a brake pedal duringbraking is converted by a master cylinder into hydraulic pressure, whichis further converted to hydraulic pressure suitable for the brakingforce of each of front and rear wheels and then transmitted to a wheelcylinder of each wheel to actuate its brake unit, thus braking thewheel.

For reducing the speed of an automobile, a large braking force isneeded; in addition, its deceleration is limited by a value dependentupon an adhesion coefficient between tires and the ground. It isrequired that the braking force for the front and rear wheels beproperly distributed by selecting a maximum oil pressure on a rear wheelbrake smaller than on a front wheel brake. It is well-known in the artthat an ideal distribution of the braking force for the front and rearwheels is such that the front brake gradually works with an increase inthe braking force therefor, that is, the individual braking forces forthe front and rear wheels bear such a relation as is represented by aquadratic curve. But the braking forces for the front and rear wheelsare usually fixed, or bear a constant relation to each other, and avariety of hydraulic pressure control valves are employed for achievingsuch an ideal distribution of the braking force.

With such hydraulic pressure control valves, an input oil pressure fromthe master cylinder is usually transmitted, as it is, to the brake unitof, for example, the front wheel, whereas, to the brake unit of the rearwheel, the input oil pressure is applied after being reduced by areciprocating motion of a plunger. These prior art valves are defectiveas discussed below. FIGS. 1(a) and (b) are a cross-sectional view of aconventional hydraulic pressure control valve and an enlarged view ofone portion. As shown in FIG. 1, a valve proper 7 has formed thereinbrake liquid inlet ports 1 and 3 and outlet ports 2 and 4. A liquidpassage from the inlet port 1 to the outlet port 2 constitutes a firsthydraulic pressure passage leading to each brake unit of the frontwheel, for instance, and a liquid passage from the inlet port 3 to theoutlet port 4 constitutes a second hydraulic pressure passage leading tothe brake unit of the front wheel, for example. In the central portionof the valve proper 7 is made a stepped hole 12a, in which a steppedplunger 5 is provided so that it may freely reciprocate. One end 5a ofthe plunger 5 partly extends into the first hydraulic pressure passageseparated by a y-seal 6 from the second hydraulic pressure passage.

The other end 5b of the plunger 5 lies in the second hydraulic pressurepassage, and a valve flange 5c of a larger diameter than that of theother end 5b is formed between the one end 5a and the other end 5b ofthe plunger. Further, a spring receiving flange 5d is formed in contactwith the valve flange 5c, defining therebetween a circular space 5e. Aspring 7a is supported by the spring receiving flange 5d and, by a plug12 threadably engaged with the valve proper, the spring 7a is urgedtoward the first hydraulic pressure passage, resulting in the plunger 5being urged by the resiliency of the spring 7a toward the firsthydraulic pressure passage.

Between the two flanges 5c and 5d, that is, in the circular space 5e, isdisposed a lip seal 23 made of a resilient material. The lip seal 23 hasits outer peripheral surface making contact with the interior surface ofthe stepped hole 12a and its inner peripheral surface projecting intothe circular space 5e between the two flanges 5c and 5d as depicted inFIG. 1(b). The lip seal 23 has formed integrally therewithsemi-spherical projections 23a at predetermined intervals on the side ofthe spring receiving flange 5d. During normal drive operation, as shownin FIGS. 1(a) and (b), the projections 23a of the lip seal 23 are incontact with the spring receiving flange 5d and the brake liquid flowinginto the stepped hole 12a from the inlet port 3 is drained out from theoutlet port 4, passing through gaps defined between adjacent ones of thesemi-spherical projections 23a. In the second hydraulic pressurepassage, since the cross-sectional areas of the plunger 5, i.e. itsother end 5b and the valve flange 5c are selected different from eachother, the brake liquid having entered from the inlet port 3 is drainedout, with its hydraulic pressure regulated by the engagement of the lipseal 23 with the outer peripheral surface of the valve flange 5c. Thatis to say, the plunger 5 lies between the first and second hydraulicpressure passages and reciprocates in dependence upon the force of thespring 7a and the hydraulic pressure of the brake liquid in the firsthydraulic pressure passage, by which the hydraulic pressure of the brakeliquid is regulated in the second hydraulic pressure passage. Betweenthe first and second hydraulic pressure passages is disposed the Y-seal6 and, during normal operation, the plunger 5 is urged toward the secondhydraulic pressure passage. Accordingly, when the first hydraulicpassage fails, the pressure on the plunger 5 decreases by that and thethe pressure regulated in the second hydraulic pressure passageincreases, resulting in the hydraulic pressure on the side of the outletport 4 to be regulated as shown in FIG. 3, line (b). The Y-seal 6 isalways exposed to the hydraulic pressures in the first and secondhydraulic pressure passages and, in addition, the plunger 5reciprocates, so that the Y-seal 6 held in contact with it is liable tobe broken.

The present invention has for its object to cure the abovesaid defect;in concrete terms, the invention is to provide a hydraulic pressurecontrol valve designed so that during normal operation no externalforces are applied to the plunger, and that upon failure of either oneof the hydraulic pressure passages leading to the brake units of thefront and rear wheels, sliding movement of the plunger is inhibited,thereby to hold the hydraulic pressure regulating mechanism inoperative.

DISCLOSURE OF THE INVENTION

The present invention is characterized first in that a first hydraulicpressure passage communicating with a brake unit of either one of frontand rear wheels and a second hydraulic pressure passage communicatingwith brake units of the other are provided; a plunger is disposed in atleast the second hydraulic pressure passage; at least one hydraulicpressure regulating mechanism is provided on the plunger in the secondhydraulic pressure passage; and blocking means is provided forinhibiting the plunger from moving in a direction in which to cut offthe brake liquid.

Accordingly, when the first or second hydraulic pressure passagecommunicating with each brake unit fails, the blocking means operates,permitting the hydraulic pressure to rise without the brake liquid beingcut off by the hydraulic pressure regulating mechanism. As a result ofthis, each brake unit on the side of the second hydraulic pressurepassage, for instance, are supplied with an increased braking force.

Secondly, the present invention is characterized in that secondhydraulic pressure passages to the hydraulic pressure of either one ofthem, and a pressurizing member for generating, by the movement of themoving member, a pressure on the plunger from at least one of thedirections radial and axial thereof and oblique thereto.

Accordingly, the blocking means is composed of only the moving memberand the pressurizing member, and hence is extremely simple structured.During normal operation, the pressurizing member is not subject to anyexternal forces unlike the Y-seal shown in FIG. 1(a). Upon failure ofeither one of the hydraulic pressure passages, the moving member detectsit and moves and, by this movement, the pressurizing member applies apressure to the plunger to retain it, that is, the movement of theplunger is immediately inhibited, so that the brake liquid is not cutoff by the hydraulic pressure regulating mechanism of the plunger.

Thirdly, the present invention is characterized in that the movingmember is constituted as a member which conforms to the outer peripheralsurface of the plunger with a slight gap defined therebetween; themoving member has on its inner peripheral surface a pressurizing areafor urging the pressurizing member in its axial direction; thepressurizing member is a member which conforms to the outer peripheralsurface of the plunger with a slight gap defined therebetween; and thepressurizing member is formed of rubber, synthetic resin or like elasticmaterial.

Accordingly, it is sufficient that the moving member has thepressurizing area. The pressurizing member is made of rubber, syntheticresin or like elastic material, so that when pressed by the pressurizingarea of the moving member, it generates a large pressurizing force forthe plunger, ensuring to inhibit the movement of the plunger.

Fourthly, the present invention is characterized in that the blockingmeans comprises a pair of moving members which are moved by thedifference in pressure between the first and second hydraulic pressurepassages and are disposed adjacent each other, a pressurizing memberwhich is urged by the movement of the moving members to develop apressurizing force in the axial direction of the plunger, and a stoppermember which supports the pressuring member.

Accordingly, the pressurizing member generates a force acting on theplunger in its axial direction to prevent its movement, ensuring toobstruct the movement of the plunger with certainty. Further, byinterposing at least one pressurizing member between the pair of movingmembers, this type of hydraulic pressure control valve can also beapplied to a dual type hydraulic pressure control valve and, further, itcan be formed as a unitary structure with the master cylinder.Especially in the case of such a unitary structure, a support shaftinserted into a shaft receiving hole is extended into the mastercylinder to hold the stopper member, by which it can be also used as astopper of the master cylinder.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(a) is a cross-sectional view of a conventional hydraulic pressurecontrol valve, and FIG. 1(b) is an enlarged cross-sectional view of itsone portion;

FIG. 2(a) is a cross-sectional view of a hydraulic pressure controlvalve according to an embodiment of the present invention, and FIG. 2(b)is explanatory of how a pressurizing force acts on a plunger in the caseof inhibiting its movement by a pressurizing member;

FIG. 3 is a graph showing the operation characteristic of the hydraulicpressure control valve illustrated in FIG. 2(a);

FIG. 4 is a cross-sectional view of a hydraulic pressure control valveaccording to another embodiment of the present invention;

FIGS. 5(a) and 5(b) are explanatory illustrations of the operation forinhibiting the movement of the plunger by pressing it with apressurizing member in the hydraulic pressure control valve shown inFIG. 4;

FIG. 6 is a cross-sectional view showing the application of blockingmeans of the hydraulic pressure control valve of FIG. 4 to a dual typehydraulic pressure control valve;

FIG. 7(a) is a cross-sectional view of a hydraulic pressure controlvalve according to another embodiment of the present invention, andFIGS. 7(b) and 7(c) are cross-sectional views taken on the line A--A inFIG. 7(a), FIG. 7(c) showing an operation in the case of failure of afirst hydraulic pressure passage; and

FIG. 8 is a cross-sectional view explanatory of the case where blockingmeans shown in FIG. 7(a) is applied to the dual type hydraulic pressurecontrol valve and this type of hydraulic pressure control valve isformed as a unitary structure with a master cylinder.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 2(a), reference numerals 1 and 3 indicate inlet ports andnumerals 2 and 4 designate outlet ports; 5 identifies a plunger; and 7denotes a valve proper. A portion of a brake liquid fed from a mastercylinder 15 enters into the valve proper 7 from the inlet port 1 and isdrained out from the outlet port 2 forming a first hydraulic pressurepassage, which usually communicates with brake units of the frontwheels. The other remaining portion of the brake liquid from the mastercylinder 15 enters into the inlet port 3 and is drained out from theoutlet port 4 and, in this time, forming a second hydraulic pressurepassage, which usually communicates with brake units of rear wheels.Accordingly, the pressure of the brake liquid passing through the firsthydraulic pressure passage is transmitted to each brake unit of thefront wheels at a value set by the master cylinder 15, whereas, in thesecond hydraulic pressure passage, the hydraulic pressure is controlledas required, by the action of a poppet valve 14 described later and thiscontrolled hydraulic pressure is transmitted to each brake unit of therear wheels.

The first and second hydraulic pressure passages form a shaft receivinghole 12a extending along the center axis of the valve proper 7, theshaft receiving hole 12a being shielded by two seal members 8 and 9 fromthe outside. As shown in FIG. 2, the shaft receiving hole 12a is usuallya stepped hole and the plunger 5 is inserted into the shaft receivinghole 12a. The rear end of the plunger 5 has mounted thereon a spring 11,which is threadably engaged with a plug 12 to press it. The plunger 5has a small-diameter portion 5g and a large-diameter portion 5h, and thestepped plunger is snugly fit into the stepped shaft receiving hole 12a.

An insertion hole 14c is formed in the large-diameter portion 5h of theplunger to extend along its center axis and, in this insertion hole 14c,a hydraulic pressure regulating mechanism such, for instance, as apoppet valve 14, as usual, a valve rod 14a projects out from asemi-spherical valve body l4d and a spring 14b is loaded on the back ofthe valve body 14d and, further, a valve seat 14e is formed by theshoulder portion of the insertion hole 14c, the valve body 14d and thevalve seat 14e constituting an openclose valve. Consequently, in thesecond hydraulic pressure passage, the brake liquid having entered fromthe inlet port 3 flows into the insertion hole 14c of the plunger andwhen the hydraulic pressure in that portion exceeds a set pressuredetermined by the spring 11, the plunger 5 moves toward the firsthydraulic pressure passage, the consequence of which the brake liquid iscut off between the valve body 14d and the valve seat 14e, permittingthe brake liquid to flow out from the outlet port 4 at a desiredhydraulic pressure.

Between the first and the second hydraulic pressure passages is providedblocking means for inhibiting the movement of the plunger 5 throughutilization of a difference in hydraulic pressure between the first andsecond hydraulic pressure passages, for instance, when the hydraulicpressure of the first hydraulic pressure passage fails. The blockingmeans comprises a moving member 10 moving substantially in parallel tothe center axis of the plunger 5 and a pressurizing member 17 which ispressed by the moving member 10. The moving member 10 comprises acylindrical form surrounding the plunger 5, with a small gap definedtherebetween, and it has a shoulder portion 10a on its inner surface,which portion 10a serves as a pressurizing area to press thepressurizing member 17. The pressurizing member 17 is usually formed tosurround the plunger 5, with a small gap defined therebetween. Thepressurizing member is usually made of rubber, synthetic resin or likeelastic material and is held between a stopper such as the plug 12 andthe moving member 10.

Accordingly, for example, when the hydraulic pressure of the firsthydraulic pressure passage fails due to accident, the movement of theplunger 5 is inhibited by the pressurizing member 17 and the poppetvalve 14 is held open, so that the characteristic shown in FIG. 3, line(b) is obtained and the brake liquid is not cut off. Therefore, thehydraulic pressure of the characteristic shown in FIG. 3, line (b) istransmitted to each brake unit of the rear wheels, performing a brakingaction without a hitch.

In other words, when the hydraulic pressure fails in the first hydraulicpressure passage, the moving member 10 is moved toward the firsthydraulic pressure passage by the difference in pressure between thefirst and second hydraulic pressure passages and the pressurizing member17 is pressed and compressed between the pressurizing area 10a of themoving member and the plug 12. In this state, since the pressurizingmember 17 is made of rubber, synthetic resin or like elastic material,it is pressed in a direction substantially parallel to the plunger 5 andas shown in FIG. 2(b), a force A is developed toward the center of theplunger 5 in the radial direction thereof, holding the plunger 5 fromits outer periphery to obstruct its movement. In consequence, asdepicted in FIG. 3, line (b), the hydraulic pressure is increased andthe brake liquid of this pressure is supplied to, for instance, thebrake units of the rear wheels.

Incidentally, the pressurizing surface of the pressurizing member 17 mayalso be roughed or grooved to provide for increased coefficient offriction.

Furthermore, it is also possible to form the pressurizing member 17 by aplate-like member, instead of such a circular form as mentioned above,so that it may engage with the rear end portion of the plunger 5.

That is to say, as illustrated in FIG. 4, the pressurizing member 17 ismade in a disc-like form, which has a centrally-disposed opening and ismounted with the opening receiving a projection 5i of the rear endportion of the plunger 5. A portion of the pressurizing member 17,usually its marginal portion, is inserted into a gap 16 between themoving member 10 and the stopper member such as the plug 12. Even withsuch an arrangement, during normal operation the hydraulic pressurecontrol valve is in such a state as depicted in FIG. 5(a) and nopressure acts on the plunger 5. But, when the hydraulic pressure failsin the first hydraulic pressure passage, the moving member 10 starts tomove to left on the drawing as shown in FIG. 5(b) and, by compressionbetween the moving member 10 and the plug 12, the pressurizing member 10develops a force toward the axial direction of the plunger 5 to preventits movement.

The arrangement of the present invention is applicable not only to thepressure control valve of the above-described type but also to such adual type pressure control valve as shown in FIG. 6. In this type ofpressure control valve, for instance, the second hydraulic pressurepassage leading to each brake unit of the rear wheels is divided intotwo, the one passage being formed between the inlet port 3 and theoutlet port 4 and the other passage being formed between an inlet port3a and an outlet port 4a, and the plunger 5 is disposed in each of thetwo passages. A disc-shaped pressurizing member 17 is engaged with theend face of each plunger 5 and the circumferential portion of eachpressurizing member 17 is pressed by each moving member 10 on eitherside of a central stopper member 18. In the case of constituting thepressurizing member 17 in such a disc-like or plate-like form asdescribed above, it may be formed as one body or an assembly of dividedpieces.

For pressing the end face of the plunger 5 by the pressurizing member 17to prevent its movement, it is also possible to employ such arrangementsas shown in FIGS. 7(a), (b), (c) and 8.

In a hydraulic pressure control valve depicted in FIG. 7(a), the firsthydraulic pressure passage is established between the inlet port 1 andthe outlet port 2, and the second hydraulic pressure passage is formedbetween the inlet port 3 and the outlet port 4. The plunger 5 isdisposed in the second hydraulic pressure passage and the poppet valve14 is mounted as a hydraulic pressure regulating mechanism on the tip ofthe plunger 5.

That is to say, the shaft receiving hole 12a is formed in the valveproper 7 to extend along its axis; the open end of the shaft receivinghole 12a is closed by the plug 12; the first and second hydraulicpressure passages are set up on both sides of a pair of moving members10 and 20; and the plunger 5 is disposed in the second hydraulicpressure passage. In the second hydraulic pressure passage, thehydraulic pressure of the brake liquid is controlled by opening andclosing of the poppet valve 14 at the tip of the plunger 5. Between thepair of moving members 10 and 20 is disposed the stopper member 18. Thestopper member 18 need not always be fixed but it may be secured to thevalve proper 7 by means of a shaft member 22. Between the stopper member18 and the end face of the plunger 5 is interposed the pressurizingmember 17 so that it may be pressed.

In this case, at least one of the moving members 10 and 20, forinstance, the moving member 10 is constructed in a cylindrical form tosurround the outer peripheral surface of the plunger 5 and the innerperipheral surface of the moving member 10 is formed to have a steppedportion, the shoulder portion of which is used as the pressurizing face10a. Accordingly, when the pressurizing member 17 is compressed betweenthe pressurizing face 10a and the stopper member 18, the movement of theplunger 5 toward the first hydraulic pressure passage can be preventedcertainly and stably.

Namely, in the hydraulic pressure control valve shown in FIG. 7(a), therear end face of the plunger 5 is supported by the pressurizing member17 and the supporting portion of the pressurizing member has asupporting recess 17a, which is usually formed in a columnarconfiguration, using rubber or like elastic material. When the hydraulicpressure of the brake liquid is normal, the moving members 10 and 20 donot move and, as shown in FIG. 7(b), the rear end portion of the plunger5 is snugly fitted into the supporting recess 17a and the plunger 5 isnot urged by the pressurizing member 17. In contrast thereto, when thehydraulic pressure fails in the first hydraulic pressure passage owingto accident or by some cause, the difference between the hydraulicpressures in the first and second hydraulic pressure passages increasesand the one moving member 10 moves toward the first hydraulic pressurepassage. At this time, the pressurizing member 17 is compressed by thepressurizing face 10a of the moving member 10 and this compressive forceis transmitted to the interior of the pressurizing member 17 to swellits supporting recess on a free surface as depicted in FIG. 7(c). As aresult of this, the plunger 5 is pressed by the end face of thepressurizing member and inhibited from moving.

Further, the hydraulic pressure control valve of FIG. 7(c) can also beconstituted as a dual type one by disposing the plunger 5 in the firsthydraulic pressure passage, too, and providing a hydraulic pressureregulating mechanism such as the poppet valve 14 at the tip of theplunger, and this type of valve can be disposed in the master cylinderas a unitary structure therewith.

That is to say, the master cylinder 15 shown in FIG. 8 is a tandem typeone and the brake liquid is supplied to respective hydraulic pressurepassages through two inlet ports 3a and 3. The plunger 5 is disposed ineach hydraulic pressure passage to extend in its axial direction and,further, the poppet valve 14 is attached to the tip of each plunger 5.By the action of the poppet valve 14, the hydraulic pressure of thebrake liquid is converted and is then transmitted to the brake unit ofthe rear wheels as usual. Also in this dual type of hydraulic pressurecontrol valve, a columnar pressurizing member 17 is disposed oppositethe rear end of each plunger and each pressurizing member 17 is heldbetween each side of the stopper member 18 and each moving member 10.Further, the stopper member 18 can be fixed by, for example, a shaftmember 22 to the casing of the master cylinder and, by extending theshaft member 22 into the master cylinder 15, it can also be utilized asa stopper for the piston of the master cylinder.

The foregoing description has been given mainly in connection withexamples which employ the poppet valve as the hydraulic pressureregulating mechanism, but other kinds of hydraulic pressure regulatingmechanisms can generally by used if they are to control the brake liquidto have a desired value of hydraulic pressure.

POSSIBILITY OF INDUSTRIAL UTILIZATION

As has been described in detail in the foregoing, according to thepresent invention, when the hydraulic pressure passage communicatingwith the brake units of either front or rear wheels fails through anaccident or by some other cause in an automobile braking system, aportion of the braking force is recovered, ensuring safety driving.During normal driving, the pressurizing member is not subject to anyexternal force, and hence is free from abrasive wear unlike the y-sealused in the prior art; accordingly, its durable length of time ismarkedly increased.

Furthermore, since the blocking means is composed of the moving memberand the pressurizing member formed of rubber, synthetic resin or likeresilient material, and hence it is extremely simple in structure andeconomical. And the blocking means can be employed not only in theautomobile braking system but also in a hydraulic machine for regulatingits pressure.

We claim:
 1. A hydraulic pressure control valve for an automobile brakemechanism having a first hydraulic pressure passage communicating witheach brake unit of one of front and rear wheels of the automobile, asecond hydraulic pressure passage communicating with each brake unit ofthe other of said front and rear wheels, a plunger disposed in at leastone of the hydraulic pressure passages and at least one hydraulicpressure regulating mechanism provided in association with the plunger,characterized in that said valve comprises:a moving member moved by adifference in pressure between the first and second hydraulic pressurepassages, said moving member being formed as a cylindrical member, andhaving an inner peripheral surface, said inner peripheral surface havinga first portion conforming to the outer peripheral surface of theplunger with a small gap defined therebetween and said inner peripheralsurface having a second portion separated from said first portion by ashoulder, said shoulder defining a pressurizing surface on said innerperipheral surface of the moving member; a pressurizing membercompressed by the movement of the moving member to apply pressure to theplunger; and a stopper member for supporting the pressurizing memberbetween the stopper member and the pressurizing surface of said movingmember; said pressurizing member being formed of an elastic material, sothat when compressed by said stopper member and the pressurizing surfaceof said moving member, said pressure member exerts a large radial forceon the plunger, thereby inhibiting the movement of the plunger.
 2. Ahydraulic pressure control valve for an automobile brake mechanismaccording to claim 1, characterized in that the pressurizing member is acircular member conforming to the outer peripheral surface of theplunger with a small gap defined therebetween.
 3. A hydraulic pressurecontrol valve for an automobile brake mechanism according to claim 1,wherein said valve is composed of a pair of moving members moved by adifference pressure between the first and second hydraulic pressurepassages and disposed adjacent each other, a pressurizing member pressedby the movement of the moving members to apply a pressure to theplunger, and a stopper member for supporting the pressurizing member. 4.A hydraulic pressure control valve for an automobile brake mechanismaccording to claim 3, characterized in that at least one of the pair ofmoving members has a pressurizing surface for holding the pressurizingmember between it and the stopper member.
 5. A hydraulic pressurecontrol valve for an automobile brake mechanism according to claim 3,characterized in that the pressurizing member is provided with apressurizing portion adjacent one end of the plunger.
 6. A hydraulicpressure control valve for an automobile brake mechanism according toclaim 3, characterized in that the stopper member is fixed by a pin to avalve proper.
 7. A hydraulic valve according to claim 3 wherein thepressurizing member is provided with a pressurizing portion opposite oneend of the plunger.